Hydraulic pressure-set liner hanger



Dec. 14, 1965 J. D. MOTT 3,22

nmnwmc PRESSURE-SET LINER HANGER Filed Nov. 28, 1962 s ShBets- -Sheet 1 Jlgo 2 BY Dec; 14, 1965 J. D. MOTT 3,223,170

HYDRAULIC PRESSURE-SET LINER HANGER Filed Nov. 28, 1962 3 Sheets-Sheet 2 JAMES 0. N07"! BHHQVHDR Dec. 14, 1965 J. D. MOTT 3,223,170

HYDRAULIC PRESSURESET LINER HANGER Filed Nov. 28, 1962 3 Sheets-Sheet :5

JAMES D. NOTT INVENTOR.

BY d

A TTORNE) United States Patent Office 3,223,171] Patented Dec. 14, 1965 3,223,170 HYDRAULIC PRESSURE-SET LINER HANGER James D. Mott, Houston, Tex., assignor to Cicero C. Brown, Houston, Tex. Filed Nov. 28, 1962, Ser. No. 240,673 11 Claims. (Cl. 166-208) This invention relates to an improved hydraulic pressure-set liner hanger for wells.

In drilling and completing wells in offshore areas, particularly where operations are conducted from a floating vessel as is now frequently done, the operating string is necessarily subjected to vertical movements due to the rise and fall of the vessel or work barge from which the operations are conducted. This creates considerable difliculty in manipulation of the operating string in the setting of liners in well bores which have been drilled, since such vertical movements, when using the more con ventional types of liner hangers, may result in premature setting of the liner hanger and other difiiculties due to the uncontrolled vertical movements of the operating string.

Accordingly, it is a primary object of the present invention to provide an improved form of hydraulic pressure-set liner hanger which will not be subject to the difficulties outlined above.

An important object is the provision of a hydraulic pressure-set liner hanger embodying features which employ the hydraulic pressure in the operating string to assure against premature setting of the hanger while it is being run.

Another object is the provision of an improved arrangement of wiper plugs for removing cement from the bore of the liner after cementing has been completed.

Still other objects are to provide a hydraulic pressureset liner hanger having improved features of construction generally enabling the hanger to be operated eficiently, without manipulation of the running string, and with a minimum of difficulty.

Other and more specific objects and advantages of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates one useful embodiment in accordance with this invention.

In the drawing:

FIG. 1 is a longitudinal cross-sectional view showing the liner hanger positioned in a well casing, the parts being shown in the positions occupied during running in of the device;

FIG. 2 is a similar view to FIG. 1 showing the hanger parts in set position in the well casing;

FIGS. 3, 4 and 5 are views similar to FIG. 2, but showing successive stages during the cementing operation conducted after the liner hanger has been set; and

FIG. 6 is a cross-section taken along line 66 of FIG. 1.

Referring to the drawing, the liner hanger comprises two major sub-assemblies suitably inter-connected as will be described subsequently, and a running tool assembly, designated generally by the letter R. The sub-asssemblies comprise the setting or anchoring assembly, designated generally by the letter S, and the liner wiper assembly, designated generally by the letter W. The liner hanger is run on the running tool assembly R, which is connected to an operating or running tubing string T, and is secured to a liner L which is to be connected to a well casing C.

The mnning tool assembly R is of the generally conventional traveling-nut type. This includes a tubular spline body 10 threadedly connected by means of a collar 11 to the tubing string T. The lower end of collar 11 defines an upper bearing race for roller bearings 12 which are supported on an annular lower bearing race 13 which projects radially beyond collar 11 and is adapted to seat on an upwardly facing shoulder 14 defined by the upper end of a tubular slip cone or expander 15 which forms a part of the setting assembly S and concentrically surrounds spline body 10. The latter carries a plurality of longitudinal spline grooves 16 to which a traveling nut 17 is connected by splines 18 extending radially inwardly of the bore of nut 17 (see FIG. 6) to permit relative longitudinal movement of the traveling nut with respect to spline body 10 while preventing relative rotation therebetween. The exterior of nut 17 carries threads 19 which are threadedly engaged in internal threads 20 provided in the wall of bore 21 of slip expander 15. As seen in FIG. 1, in the running-in position of the tool, traveling nut 17 is engaged with threads 20 and is at the lower end of its travel. It will be understood that upon relative rotation between tubing string T and setting assembly S which will actuate threads 19, 20, the splined connection between nut 17 and spline body 10 will force nut 17 to move upwardly relative to slip expander 15 until the nut is disengaged from threads 20, thereby releasing the connection between the running assembly R and the setting assembly S, as will be more fully described hereinafter. The lower end of spline body 10 is internally threaded at 22 to receive the upper end of a tubular inner mandrel 23 which is radially spaced from the bore wall of expander 15.

The setting assembly includes, as noted, slip expander 15 which is provided externally at its lower end with a downwardly and inwardly sloping conical slip-engaging surface 24. Slip expander 15 is counterbored from its lower end to provide the downwardly facing internal shoulder 25 and is also internally threaded at 26 to receive the upper end of an outer tubular mandrel 27 concentric with inner mandrel 23. An upper seal ring 28 is clamped between the upper end of outer mandrel 27 and shoulder 25 to close the upper end of annular space 29 defined between the inner and outer mandrels. The lower end of outer mandrel 27 is provided with an external enlargement 30 which defines an upwardly facing annular shoulder 31 surrounding the exterior of outer mandrel 27. Enlargement 30 is counterbored from its lower end and is internally threaded at 32 to receive the upper end of a coaxial extension 33 of outer mandrel 27. The counterbore in enlargement 30 defines an internal downwardly facing shoulder 34 in the bore of enlargement 30 and a lower seal ring 35 is clamped between shoulder 34 and the upper end of extension mandrel 33, thereby closing off the lower end of annular space 29. The lower end of extension mandrel 33 is provided with an external enlargement 36 defining an upwardly facing annular shoulder 37 surrounding extension 33 in longitudinally spaced relation to the lower end 38 of enlargement 30. An annular piston 39 is slidably disposed about the lower end of outer mandrel 27 immediately above shoulder 31. The pressure-actuatable area of the lower end of piston 39 is made substantially equal to the area of shoulder 31 which operates as a cylinder head for a piston chamber 40 which is defined between the cylinder head and the lower end of piston 39. Chamber 40 is in communication with annular space 29 by means of ports 41 extending through the wall of outer mandrel 27 immediately above enlargement 30. Ports 42 are provided through the wall of inner mandrel 23 at a point above lower seal ring 35 to provide pressure fluid communication between the bore 23a of the inner mandrel and annular space 29. A suitable seal 43 is provided between piston 39 and the exterior of outer mandrel 27 above ports 41 to prevent leakage of lfuid upwardly between the piston and outer mandrel. Piston 39 is provided with an elongate cylindrical skirt 44 which extends slidably about the exterior of enlargement 30 to a point adjacent shoulder 37 of enlargement 36. By reason of the difference between the external diameter of mandrel extension 33 and the inner diameter of skirt 44, there is provided an annular chamber 45 which is closed at its lower end by means of a cylinder cap 46 which is suitably secured to the lower end of skirt 44 and is slidably disposed about the exterior of mandrel extension 33, being provided also with a seal packing 47 to seal between cylinder cap 46 and the exterior of mandrel extension 33. The annular space 45 between mandrel extension 33 and sleeve 44 is greater in width than the width of piston chamber 40, so that the areas defined by shoulder 38 and the upper end 46a of cylinder cap 46 are necessarily correspondingly greater than the area of shoulder 31 and the corresponding pressure-actuatable area of piston 39. The purpose of this difference in areas will be explained more fully hereinafter. Upper end 46a of cylinder cap 46 functions as a second piston as will appear subsequently.

Ports 48 are provided through the wall of mandrel extension 33 to provide pressure fluid communication between the annular space 49 below lower seal ring 35 between inner mandrel 23 and mandrel extension 33 and the interior of annular space 45, which constitutes a lower piston chamber, as distinguished from the upper piston chamber 40. Ports 50 provide pressure fluid communication between the bore of inner mandrel 23 and annular space 49.

A plurality of angularly spaced toothed slips 70 are disposed about conical surface 24 of the slip expander and are mounted on flexible arms 71, the lower ends of which are rigidly secured to the upper end of piston 39. It will be evident that upward movement of the latter relative to the slip expander will drive slips 70 up over conical surface 24 which by reason of the cooperating tapering surfaces and the flexibility of arms 71, will wedge the slip outwardly into anchoring engagement with casing C. A connector sleeve 72 is threadedly secured to the upper end of slip expander 15 and surrounds the running assembly R. Sleeve 72 will ordinarily be only a few feet long but may serve as a connector for an upward extension of liner L, should it be desired, after liner L is set, to extend the liner to the surface. The upper end of liner L is threadedly received in counterbore 52 provided in lower enlargement 36. The latter defines an internal shoulder 53 which forms a seat for a support ring 54 which is clamped against shoulder 53 by the upper end of the liner. Support ring 54 has one or more longitudinal openings 55 therethrough.

Wiper assembly W includes a tubular wiper support member or catcher sub 56 which is substantially smaller in external diameter than the internal diameter of liner L and is mounted in the bore of the latter. Catcher sub 56 is provided with a perforate nose wall 56a and is secured at its upper end to support ring 54 by means of shear pins 57 which extend radially through an annular flange 58 which extends upwardly from the inner edge of support ring 54. The difference in diameter between catcher sub 56 and liner L defines the annular space 59 which is closed at its upper end by means of an annular wiper plug 60, constructed of flexible resilient material, which is securely mounted on the exterior of catcher sub 56 in wiping and sealing engagement with the inner wall of liner L. A latch dog 61 is mounted on the exterior of catcher sub 56 just below wiper plug 60 and is adapted for latching beneath an internal shoulder 62 formed in the bore of a latch ring 63 mounted adjacent the lower end of liner L, when the catcher sub and its associated elements are moved downwardly in the liner, as will be explained hereinafter. The lower end of liner L is connected to a foot piece 64 which terminates in the usual cementing shoe 65 having openings 65a through which cement may be displaced from the interior of the liner into the annular space between the liner and well casing C. The bore wall of catcher sub 56, at a point substantially opposite plug 60, is provided with a plurality of inwardly projecting, downwardly facing buttress teeth 66. A shear sleeve 67 is mounted over buttress teeth 66 and is secured to the wall of catcher sub 56 by means of shear pins 68 which are made substantially weaker than shear pins 57. At a point below wiper plug 60, the wall of catcher sub 56 is provided with a plurality of ports 73 to provide fluid communication between the bore of the catcher sub and annular space 59.

Operation of the device is as follows: The liner hanger, connected to liner L and to operating tubing string T, as shown in FIG. 1, is run into the well bore through casing C to the point at which the liner is to be secured to the casing. Normally as the liner hanger and liner are being run, washing fluid will be circulated through the operating string and back through the annulus between the liner and the casing. The pressure of this fluid or any other fluid pressure in the tubing string will be transmitted through ports 42 and 41 to pressure chamber and also through ports 50 and 48 to pressure chamber 45. As the string of tools moves downwardly, should the liner bump on some obstacle which would tend to move slips 70 up over slip expander 15 and prematurely set the liner hanger, this can be readily overcome by lifting upwardly on the tubing string to relieve the expansive force on the slips. At the same time, the fluid pressure acting on the differential pressure-actuatable areas in pressure chambers 40 and will produce a greater force on lower piston 46a than on piston 39 by reason of the greater area of piston 46a. The resulting greater force on the lower piston will act through skirt 44 to pull piston 39 downwardly and thereby pull slips 7 0 to their retracted position and free the liner hanger for continued downward movement. This arrangement of differential area pistons subjected to the common source of fluid pressure in the tubing string is an important improvement which assures against premature setting of the liner hanger while the liner is being run.

When the liner has attained the proper location in casing C, lowering will be stopped and a first plug, designated generally by the letter P will be put into the tubing string. Plug P is of a generally conventional design comprising a flexible resilient body 80 provided with a plurality of upwardly tapering flexible lips 81 about its exterior which are adapted to have slidable sealing engagement with the wall of inner mandrel 23. At its lower end plug body 80 is secured to a metallic end-piece 82 dimensioned to slide freely inside the bore of catcher sub 56 and to engage the upper end of shear sleeve 67, as shown particularly in FIG. 2. The length of the plug body is made such that when seated on shear sleeve 67, it will extend to a height sufiicient to seal. off between ports 42 and in the inner mandrel, thereby isolating pressure chamber 45 from the pressures in the inner mandrel and the tubing string. With the ports 50 thus sealed off, the pressure on the body of well fluid will be exerted through ports 42 and 41 in pressure chamber 40 against piston 39 and will then force the latter upwardly, moving slips 70 over slip expander 15 until the slips are effectively anchored in the wall of easing C. When the slips are set, some tubing weight will be set down on slip expander 15 to more firmly anchor the slips to the casing wall. As the pressure in the body of the well fluid in the operating string continues to build up, shear pins 68, which secure shear sleeve 67 to catcher sub 56, will be broken and plug P together with shear sleeve 67, will be forced downwardly to the lower end of catcher sub 56 where they will be held by lower end wall 56a of the catcher sub, as best seen in FIG. 3. The displacement of plug P to the bottom of the catcher sub will open ports 73 in the latter for circulation from the bore of the operating string into annular space 59 and thence through the openings in cementing shoe 65 into the annular space between liner L and easing C, as seen in FIG. 3.

When plug P has been moved to the bottom of the catcher sub to open ports 73, the tubing string will be rotated to the right which will actuate traveling nut 17, causing it to move upwardly out of its threaded connection with slip expander to the position illustrated in FIG. 3. This releases the connection between the operating string and the setting and wiping assemblies.

The pre-calculated body of cement will then be introduced into the tubing string and will be followed by a second plug, designated generally by the letter P (FIG. 4). The quantity of cement thus introduced will have been pre-calculated in the conventional fashion to fill the annular space between the liner and the casing to the desired height, which will be usually to some suitable point above the setting assembly S. The plug P is of the same general form as plug P but the nose piece 82a is modified to carry about its exterior a set of anchor slips 84 which are adapted to ratchet over teeth 66, which will have been uncovered by the displacement of shear sleeve 67, and anchor therein so as to lock plug P against upward movement. The inwardly projecting teeth 66 will also form a seat for plug P The latter, as indicated above, is generally similar in shape to plug P being adapted to seal with the bore of inner mandrel 23 in order to seal off the latter between ports 42 and 50. A body of displacing fluid F will be pumped into the tubing string behind plug P and its pressure will be increased on seated plug P until sufiicient force is generated to break shear pins 57, whereupon catcher sub 56, plug P and wiper plug 60 will be released for movement downwardly through the bore of the liner. The downward movement of these parts, including wiper plug 60, will wipe the cement out of the interior of the liner and as the wiper plug and the catcher sub move downwardly, latch dog 61 will be moved below latch ring 63 so as to latch under shoulder 62 and effectively prevent upward movement of the catcher sub and the plugs supported thereon and contained therein, thereby preventing any back-flow of the cement. This position of the catcher sub, wiper plug and plugs P and P are best seen in FIG. 5. This operation will complete the setting and cementing operations and since traveling nut 17 has been previously released from slip expander 15, as previously described, it is only necessary to pull the tubing string upwardly in order to withdraw the running assembly and inner mandrel 23 from the hanger assembly and withdraw it from the Well, this operation, of course, being conducted before the cement has set.

From the foregoing, it will be seen that the present invention provides a liner hanger construction which may be operated without any longitudinal manipulation of the operating string and which is not subject to premature setting as a result of any uncontrolled longitudinal or rotational movements of the operating string. The hydraulic pressure-setting of the anchor slips assures firm anchorage of the liner hanger and the differential piston arrangement, previously described, provides the important improvement of preventing premature setting of the liner hanger.

It will be understood that various alterations and changes may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. In a hydraulic pressure-set liner hanger, an anchor assembly comprising a tubular mandrel connectible to a liner to be run inside a well casing, a slip expander mounted on the mandrel, anchor slips slidably supported on the mandrel below the slip expander for movement upwardly relative thereto to engage the well casing, a running assembly comprising a tubular body connectible to a tubular operating string and including means forming a releasable connection between the running assembly and the anchor assembly actuatable by relative rotation between the tubular body and the anchor assembly to release the running assembly from the anchor assembly, slip-actuating means comprising a cylinder sleeve connected to the slips and slidably disposed about the exterior of the mandrel, longitudinally spaced upper and lower annular pistons carried by said sleeve in slidable sealing engagement with the exterior of the mandrel, the lower piston having greater pressure-actuatable area than the upper piston, barrier means extending from the mandrel into said sleeve forming a partition in said sleeve defining upper and lower pressure chambers for the respective pistons, conduit means including longitudinally spaced upper and lower port means in said mandrel arranged to direct pressure fluid from the interior thereof separately to the respective pressure chambers, the greater pressure-actuatable area of said lower piston being operative to urge said slips downwardly to non-actuated position relative to the slip expander, and plugging means insertable in said mandrel to close off the bore of the mandrel between said port means whereby to direct pressure fluid solely to said upper piston to actuate the anchor slips.

2. In a hydraulic pressure-set liner hanger according to claim 1, wherein said conduit means comprises partition elements extending between said tubular body and said mandrel to define separate fluid communication paths between the interior of said tubular body and said upper and lower port means.

3. In a hydraulic pressure-set liner hanger according to claim 1, wherein said conduit means comprises an extension of said tubular body coaxially disposed in the bore of said mandrel to define an annular space therebetween, upper and lower passages through the wall of said extension communicating the bore thereof with said annular space, and partition means positioned in said annular space to aflord separate fluid communication paths between the upper and lower passages and the respective upper and lower port means.

4. In a hydraulic pressure-set liner hanger, an anchor assembly comprising a tubular mandrel connected to a liner to be run inside a well casing, a slip expander mounted on the mandrel, anchor slips slidably supported on the mandrel below the slip expander for movement upwardly relative thereto to engage the well casing, a running assembly comprising a tubular body connectible to a tubular operating string and including means forming a releasable connection between the running assembly and the anchor assembly actuatable by relative rotation between the tubular body and the anchor assembly to release the running assembly from the anchor assembly, slip-actuating means comprising a cylinder sleeve connected to the slips and slidably disposed about the exterior of the mandrel, longitudinally spaced upper and lower annular pistons carried by said sleeve in slidable sealing engagement with the exterior of the mandrel, the lower piston having greater pressure-actuatable area than the upper piston, barrier means extending from the mandrel into said sleeve forming a partition defining upper and lower pressure chambers for the respective pistons, conduit means including longitudinally spaced upper and lower port means in said mandrel arranged to direct pressure fluid from the interior thereof separately to the respective pressure chambers, the greater pressure-actuatable area of said lower piston being operative to urge said slips downwardly to non-actuated position relative to the slip expander, plugging means insertable in said mandrel to close ofi the bore of the mandrel between said port means whereby to direct pressure fluid solely to said upper piston to actuate the anchor slips, and a wiper assembly mounted in the bore of said liner for downwardly slidable wiping engagement therewith to displace fluids from said liner.

5. In a hydraulic pressure-set liner hanger according to claim 4 wherein said wiper assembly includes a tubular wiper support member, a pressure-frangible connection between said support member and the liner, an annular resilient sleeve element mounted on the support member to extend into slidable sealing engagement with the wall of the liner, and means in the bore of said support member to receive a plugging member from the mandrel whereby fluid pressure may be applied through said mandrel to release said frangible connection and move said wiper assembly downwardly through said liner.

6. In a hydraulic pressure-set liner hanger according to claim 4 wherein said wiper assembly includes a tubular support member, a pressure-frangible connection between said support member and the liner, an annular resilient sleeve element mounted on the support member to extend into slidable sealing engagement with the wall of the liner, means in the bore of said support member to receive a plugging element from the mandrel to close ofi the bore of the support member whereby fluid pressure may be applied through the mandrel to release said frangible connection and move said wiper assembly downwardly through the liner, and cooperating latch elements carried by the support member and the liner engageable at the lower terminus of the travel of the wiper assembly to lock the same to the liner against reverse movement therein.

7. In a hydraulic pressure-set liner hanger, an anchor assembly comprising a tubular mandrel connectible to a liner to be run inside a well casing, a slip expander mounted on the mandrel, anchor slips slidably supported on the mandrel below the slip expander for movement upwardly relative thereto to engage the well casing, a running assembly comprising, a tubular body adapted for Connection to a tubular operating string and slidably disposed in the bore of the mandrel, means forming a releasable connection between said body and the anchor assembly, said means including a nut member having threaded connection to said expander and longitudinally slidable splined connection to said tubular body actuatable by relative rotation between said body and the anchor assembly to release said body from the anchor assembly, fluid pressure-actuated means mounted on the mandrel for moving said anchor slips upwardly relative to said expander, said fluid pressure-actuated means comprising a cylinder sleeve slidably disposed about the exterior of the mandrel, longitudinally spaced upper and lower annular pistons carried by said sleeve in slidable sealing engagement with the exterior of the mandrel, the lower piston having greater pressure-actuatable area than the upper piston, barrier means extending from the mandrel into said sleeve forming a partition defining upper and lower pressure chambers for the respective pistons, conduit means including longitudinally spaced upper and lower port means in said mandrel arranged to direct pressure fluid from the interior thereof separately to the respective pressure chambers, the greater pressureactuatable area of said lower piston being operative to urge said slip downwardly to non-actuated position relative to the slip expander, and plugging means insertable in said mandrel to close oif the bore of the mandrel between said port means whereby to direct pressure fluid solely to said upper piston to actuate the anchor slips.

8. In a hydraulic pressure-set liner hanger, an anchor assembly comprising a tubular mandrel connected to a liner to be run inside a well casing, a slip expander mounted on the mandrel, anchor slips slidably supported on the mandrel below the slip expander for movement upwardly relative thereto to engage the well casing, a running assembly comprising, a tubular body adapted for connection to a tubular operating string and slidably disposed in the bore of the mandrel, means forming a releasable connection between said body and the anchor assembly, said means including a nut member having threaded connection to said slip expander and longitudinally slidable splined connection to said tubular body actuatable by relative rotation between said body and the anchor assembly to release said body from the anchor assembly, fluid pressure-actuated means mounted on the mandrel for moving said anchor slips upwardly relative to said expander, said fluid pressure-actuated means comprising a cylinder sleeve slidably disposed about the exterior of the mandrel, longitudinally spaced upper and lower annular pistons carried by said sleeve in slidable sealing engagement with the exterior of the mandrel, the lower piston having greater pressure actuatable area than the upper piston, barrier means extending from the mandrel into said sleeve forming a partition defining upper and lower pressure chambers for the respective pistons, conduit means including longitudinally spaced upper and lower port means in said mandrel arranged to direct pressure fluid from the interior thereof separately to the respective pressure chambers, the greater pressure-actuatable area of said lower piston being operative to urge said slips downwardly to non-actuated position relative to the slip expander, plugging means insertable in said mandrel to close off the bore of the mandrel between said port means whereby to direct pressure fluid solely to said upper piston to actuate the anchor slips, and a wiper assembly mounted in the bore of said liner for downwardly slidable wiping engagement therewith to displace fluids from said liner.

9. In a hydraulic pressure-set liner hanger, an anchor assembly comprising a tubular mandrel connectible to a liner to be run inside a well casing, a slip expander mounted on the mandrel, anchor slips slidably supported on the mandrel below the slip expander for movement upwardly relative thereto to engage the well casing, a running assembly comprising a tubular body connectible to a tubular operating string and including means forming a releasable connection between the running assembly and the anchor assembly actuatable by relative rotation between the tubular body and the anchor assembly to release the running assembly from the anchor assembly, slip-actuating means comprising a cylinder sleeve connected to the slips and slidably disposed about the exterior of the mandrel, longitudinally spaced upper and lower annular pistons carried by said sleeve in slidable sealing engagement with the exterior of the mandrel, the lower piston having greater pressure-actuatable area than the upper piston, shoulder means extending from the mandrel into said sleeve forming a partition in said sleeve defining upper and lower pressure chambers for the respective pistons, conduit means including longitudinally spaced upper and lower port means in said mandrel arranged to direct pressure fluid from the mandrel separately to the respective pressure chambers, the greater pressure-actuatable area of said lower piston being operative to urge said slips downwardly to non-actuated position relative to the slip expander, and plugging means insertable in said mandrel to close oif the bore of the mandrel between said port means whereby to direct pressure fluid solely to said upper piston to actuate the anchor slips.

10. In a hydraulic pressure-set liner hanger, an anchor assembly comprising a tubular mandrel connected to a liner to be run inside a well casing, a slip expander mounted on the mandrel, anchor slips slidably supported on the mandrel below the slip expander for movement upwardly relative thereto to engage the well casing, a running assembly comprising a tubular body connectible to a tubular operating string and including means forming a releasable connection between the running assembly and the anchor assembly actuatable by relative rotation between the tubular body and the anchor assembly to release the running assembly from the anchor assembly, slip-actuating means comprising a cylinder sleeve connected to the slips and slidably disposed about the exterior of the mandrel, longitudinally spaced upper and lower annular pistons carried by said sleeve in slidable sealing engagement with the exterior of the mandrel, the lower piston having greater pressure-actuatable area than the upper piston, shoulder means extending from the mandrel into said sleeve forming a ,partition in said sleeve defining upper and lower pressure chambers for the respective pistons, conduit means including longitudinally spaced upper and lower port means in said mandrel arranged to direct pressure fluid from the mandrel separately to the respective pressure chambers, the greater pressure-actuatable area of said lower piston being operative to urge said slips downwardly to non-actuated position relative to the slip expander, plugging means insertable in said mandrel to close off the bore of the mandrel between said port means whereby to direct pressure fluid solely to said upper piston to actuate the anchor slips, and a wiper assembly mounted in the bore of said liner for downwardly slidable wiping engagement therewith to displace fluids from said liner.

11. In a hydraulic pressure-set liner hanger according to claim 10 wherein said wiper assembly includes a tubular wiper support member, a pressure-frangible connection between said support member and the liner, an annular resilient sleeve element mounted on the support member to extend into slidable sealing engagament with the wall of the liner, and means in the bore of said support member to receive a plugging member from the mandrel whereby fluid pressure may be applied through said mandrel to release said frangible connection and move said Wiper assembly downwardly through said liner.

References Cited by the Examiner UNITED STATES PATENTS 2,436,525 2/1948 ODonnell 166208 2,795,281 6/1957 Christian 166-120 3,083,769 4/1963 Brown 166-120 3,102,595 9/1963 Fisher l66156 CHARLES E. OCONNELL, Primary Examiner. 

1. IN A HYDAULIC PRESSURE-SET LINER HANGER, AN ANCHOR ASSEMBLY COMPRISING A TUBULAR MANDREL CONNECTIBLE TO A LINER TO BE RUN INSIDE A WALL CASING, A SLIP EXPANDER MOUNTED ON THE MANDREL, ANCHOR SLIPS SLIDABLY SUPPORTED ON THE MANDREL BELOW THE SLIP EXPANDER FOR MOVEMENT UPWARDLY RELATIVE THERETO TO ENGAGE THE WELL CASING, A RUNNING ASSEMBLY COMPRISING A TUBULAR BODY CONNECTIBLE TO A TUBULAR OPERATING STRING AND INCLIDING MEANS FORMING A RELEASABLE CONNECTION BETWEEN THE RUNNING ASSEMBLY AND THE ANCHOR ASSEMBLY ACTUATABLE BY RELATIVE ROTATION L BETWEEN THE TUBULAR BODY AND THE ANCHOR ASSEMBLY TO RELEASE THE RUNNING ASSEMBLY FROM THE ANCHOR ASSEMBLY, SLIP-ACTUATING MEANS COMPRISING A CYLINDER SLEEVE CONNECTED TO THE SLIPS AND SLIDABLY DISPOSED ABOUT THE EXTERIOR OF THE MANDREL, LONGITUDIALLY SPACED UPPER AND LOWER ANNULAR PISTONS CARRIED BY SAID SLEEVE IN SLIDABLE SEALING ENGAGEMENT WITH THE EXTERIOR OF THE MANDREL, THE LOWER PISTON HAVING GREATER PRESSURE-ACTUATABLE AREA THAN THE UPPER PISTON, BARRIER MEANS EXTENDING FROM THE MANDREL INTO SAID SLEEVE FORMING A PARTITION IN SAID SLEEVE DEFINING UPPER AND LOWER PRESSURE CHAMBERS FOR THE RESPECTIVE PISTONS, CONDUIT MEANS INCLUDING LONGITUDINALLY SPACED UPPER AND LOWER PORT MEANS AND SAID MANDREL RERANGED TO DIRECT PRESSURE FLUID FROM THE INTERIOR THEREOF SEPARATELY TO THE RESPECTIVE PRESSURE CHAMBERS, THE GREATER PRESSURE-ACTUATABLE AREA OF SAID LOWER PISTON BEING OPERATIVE TO URGE SAID SLIPS DOWNWARDLY TO NON-ACTUATED POSITION RELATIVE TO THE SLIP EXPANDER, SAID PLUGGING MEANS INSERTABLE IN SAID MANDREL TO CLOSE OFF THE BORE OF THE MANDREL BETWEEN SAID PORT MEANS WHEREBY TO DIRECT PRESSURE FLUID SOLELY TO SAID UPPER PISTON T ACTUATE THE ANCHOR SLIPS. 